Electrical connector and connection



Feb. 11, 1964 R. J. KINKAID 3,120,990

ELECTRICAL CONNECTOR AND CONNECTION Filed Oct. 15, 1958 2 Sheets-Sheet 1 IN VENTOR.

f Robevt JKinkoid I BY M,MW

Feb. 11, 1964 R. J. KINKAID ELECTRICAL CONNECTOR AND CONNECTION 2 Sheets-Sheet 2 Filed Oct. 15, 1958 INVENTOR. Roberr d. Kinkaid BY United States Patent Ofiice 3,l2@,h% Patented Feb. 11, 1964 This invention relates to electrical connectors, particularly of the disconnect type.

One widely used type of disengageable electrical connection comprises a tab or the like which is received within a complementary receptacle having a resilient means for holding the tab and pressing portions of its surface against portions of the surface of the receptacle. Connectors of this general type are useful where a reliable connection is required which must be disengaged repeatedly for servicing or repairs or for other purposes. A connector of this type is shown, for example, in United States patent to Hammell No. 2,791,755.

It will be apparent that, for maximum convenience in use, the connectors in a disconnect type of electrical connection must be capable of being engaged with, and disengaged from, each other with relative ease. Preferably, the connectors should be engageable and disengageable manually and without the exertion of an unduly hi h force or the use of a specialized tool. However, the connection must also have the requisite ability to conduct electricity and must be capable of withstanding, without becoming disengaged, those accidental or unavoidable forces to which it may be subjected. The last mentioned consideration is of some importance in view of the fact that wires are frequently subjected to accidental or unavoidable stresses as when a technician working with the wires accidentally pulls on them.

Many of the prior art disconnect type of connectors are constructed in a manner such that the accidental forces to which the connected conductors may be subjected tend to disengage the mating parts of the connection; in other words these accidental forces act on the connection in the same manner as the intentional forces which a technician would apply if he wished to disengage the parts. It is obvious then, that if the connector is made in a manner such that it will withstand a relatively high accidental force, it will require the same relatively high force to intentionally engage or disengage the parts.

An additional feature of some prior art disconnects is that those elements of the mating connectors which function as the electrical contacting surfaces are either structurally closely related to, or are the same elements as, those which function as the mechanical connection between the parts. With such an arrangement, the imposition of an accidental force tends to disturb the electrical connection and additionally, if the connection is dependent on the resiliency of the mating connectors, the electrical integrity of the junction may be impaired after the parts have been subjected to repeated accidental or intentional forces. It would be desirable to separate the electrical and the mechanical functions of a disconnect to avoid the foregoing possibilities.

It is among the objects of the present invention to provide disconnect types of electrical connectors which can be intentionally disengaged and engaged with relative case but which are highly resistant to accidental disengagement. A. further object is to provide disconnect types of electrical connectors in which the connector elements which establish the electrical connection are separate from, and are not substanti .lly afiected by, those elements which establish the mechanical connection. A further object is to provide a disconnect in which the receptacle extends laterally of the axis of the conductor to which the receptacle is secured. A still further object is to provide a receptacle which receives a mating tab or the like in a manner such that a plurality of such receptacle can be mounted on a single elongated tab if desired.

The foregoing and other objects are achieved in a connector comprising an apertured web having electrical contacting means extending therefrom. The contacting means provides contact portions which are in substantial alignment with the aperture. The web is secured to a conductor, such as a wire, eccentrically of the aperture and, in use, a mating connector having a cross sectional configuration similar to, but smaller than, the aperture is inserted through the aperture and into engagement with the contact portions. Since the conductor is secured to the web eccentrically of the aperture, if a force is applied to the wire, the web is cocked relative to the mating connector and jams thereagainst. Thus, the force is transmitted through the connection without disturbing the electrical contacting surfaces. The connection can, however, be disengaged by exerting an axial pull on the web and the mating connector.

In the drawing:

FIGURE 1 is a plan view of a preferred form of sheet metal blank from which connectors in accordance with the invention are formed;

FIGURE 2 is a side elevation view of an uncrimped connector formed from the blank of FIGURE 1;

FIGURE 3 is a perspective view of the connector of FIGURE 2;

FIGURE 4 is a perspective view of the connector after crimping onto a wire and showing a tab in engaged relationship with the connector;

FIGURE 5 is a View taken along the lines 55 of FIGURE 4;

FIGURE 6 is a side view of a pair of connectors which are engaged with a single tab extending from a connector block;

FIGURE 7 is a view showing a pair of wires extending normally of each other and connected by connectors of the type shown in the preceding figures;

FIGURE 8 is a view showing a connector in accordance with the invention but having the wire extending obliquely; and

FIGURES 9 and 10 are alternative embodiments.

Referring rst to FIGURES 2, 3 and 4, a preferred form of connector in accordance with the invention comprises a receptacle portion generally indicated at 2, a ferrule forming portion 4, and a second ferrule forming portion 6. When the connector is crimped onto a conductor such as the end of a wire, the ears 8 which comprise ferrule forming portion 6 are curled over the insulation of the conductor 9 into gripping engagement therewith, and the cars 16 of ferrule forming portion 4 are curled toward each other and downwardly into engagement with the strands or conducting core of the wire as is commonly known. It will be appreciated that the present invention is concerned primarily with the receptacle portion 2 of the connector and that a variety of types of crimps or other connections might be employed to secure this receptacle to a conductor.

The receptacle comprises a web portion 12 having a slot lid extending longitudinally therein. This slot should be of a size sufficient to receive the complementary tab with which the receptacle is to be used and to this end, should be somewhat larger than the tab although it should not be excessively oversized for reasons which will be apparent from a description which follows. A pair of ears lo, 11% extend from the longitudinal edges of web portion 12 in parallel spaced apart relationship, the normal spacing between these cars being less than the thickness of the tab so that the ears will be biased apart upon insertion of the tab. In the disclosed embodiment, the base portions 20 of the ears, those portions adjacent the web portion 12, extend obliquely of the planes of the tabs and of the planes of the web 12. This arrangement contributes to the resiliency or the sprmginess of the ears and further permits the ears to move substantially normally of each other when they are sprung apart as the tab is inserted. It will also be appreciated that where the web is substantially wider than the thickness of the tab, it is necessary to bend the cart inwardly somewhat since they must be spaced apart by a distance less than the thickness of the tab.

Ears 16, 18 are advantageously provided with resilient means acting along their lateral edges to couple them together and urge them towards each other while pernnttingthese ears to move relatively apart as the tab is inserted. In this disclosed embodiment, this resilient means takes the form of arms 24 which extend laterally from the sides of ear 15 and are curled around the ends of the ears so that the edges 26 bear against the external surface of car 18. In effect, these resilient arms of ear 16 constitute circular springs which are c-shaped in configuration and which normally bias the ears towards each other but which permit the ears to move apart.

in use, the receptacle is connected to a complementary tab 28 by merely moving the tab relatively through slot 14 and between ears 16, 18. As this is done, the ears are cammed apart and the springs 24 are lightly stressed thereby to press the ears firmly against the faces of the tab. If desired, detent means indicated at 22 may be provided on the tab and on one of the ears to serve as an interlock between the two parts.

While the preferred method of assembling the tab 28 to the receptacle is as shown in FIGURE 4, it is also possible and entirely feasible to assemble the parts by inserting the tab relatively between the plates or ears 16, 18 and then through the elongated slot 14. The latter method might be found desirable under some conditions as where difiiculty is encountered in leading the conductor 9 up to the tab. It should also be mentioned that under some circumstances it might be found to be desirable to bend the connector so that the crimp portions 4 and 6 extend in a direction other than that shown in FIGURE 4, for example it may be desirable to form the crimped portions obliquely as shown in FIGURE 8 or through an angle of 90 from the position shown in FIGURE 4 so that the axis of the wire 9 extends parallel to, and spaced from, the receptacle which receives tab 28.

A preferred method of forming connectors in accordance with the invention is first to form a metal strip blank as shown in FIGURE 1. In this figure, the structural parts of the blank are denoted by the same reference numerals as those used with reference to the finished connection in FIGURE 3 but with prime marks appended. Thus it will be apparent that the springs 24 are formed from the arms 24' which in turn extend laterally from the side 16' of the blank. The side 16' of course becomes ear 16 while the sections 20 form in the finished connector the loose portions it} of ears.

A salient advantage of the invention is that it is virtually impossible unintentionally to disengage the tab 28 from the receptacle when a force is applied to conductor '9. By way of example, if the conductor is pulled upwardly or downwardly as viewed in FIGURE 4, the receptacle will be cocked relative to the tab, by virtue of the fact that the force is applied eccentrically, and will jam against the tab. However, the receptacle can be intentionally disengaged from the tab by merely grasping both parts and moving them axially apart. It will be apparent that conductor 9 can be pulled in any direction 'without danger of accidental disengagement. With the embodiment of FIGURE 7, where tab 28 is secured to .a conductor, it is also apparent that the connection can- ;not be disengaged by pulling on the wires. The force re- .guired intentionally to disengage the parts by pulling 4 them apart axially is determined by the resilience of the ears 9 and the springs 24 and can thus be set at any desired level.

Another important advantage of the invention is that any forces applied to the wires and transmitted through the connection are transmitted mainly from the edges of the slot to the tab and not across the electrical contacting surfaces of the tab and the ears 16, 18. These surfaces may move relatively to each other by a slight amount when a force is first applied and the receptacle cocked but they are substantially unstressed at all times and need perform no load carrying function. Additionally, the resiliency of ears 16, 18 towards the faces of the tab is not damaged if one of the wires 9 is pulled since the mechanical load is transmitted at the aperture. Thus, these cars can not be sprung by overstressing as with some prior art devices.

As shown in FIGURE 6, a plurality of terminals can be assembled to a single tab such as the elongated tabs as shown in FIGURE 6. Quite frequently it is desirable to form a common junction among several wires. Since the tab in the instant invention extends entirely through the receptacle and has a free end on each side thereof, an additional receptacle can be attached to the same tab. In FIGURE 6, several tabs are shown projecting from a connector block 3t) which might be employed to join commonly several such connectors.

It will be noted that standard crimps can be used in the embodiment of FIGURE 2 since the ferrule forming portions 4, 6 extend axially away from the web. In the past with some types of flag type disconnects, it has been found necessary to devise specialized crirnps from connectors of this type because of the shape and design of the receptacle.

Alternative forms of the invention will be apparent from the foregoing description. For example, rather than have the aperture in the form of a slot and the mating connector is in the form of a tab as in FIGURE 2, an aperture of another shape might be provided. The mating connector would then have a shape which would be substantially similar to and slightly smaller than the aperture so as to achieve the cocking and jamming effect described above.

FIGURES 9 and 10 show embodiments having alternative forms of eelctrical contacting surfaces. In FIGURE 9 the ears 16a, 18a are merely bent inwardly towards each other and in alignment with the slot. In FIGURE 10, the contacting surfaces of the receptacle are in the form shown in the aforementioned I-Iammell patent; that is the curled over wings press the tab against the surface of ear 18b. In both of these embodiments, the advantages of stress transmission through the slot and improbability of accidental disengagement are realized.

Change in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

I claim:

1. An electrical connector comprising a contact portion and a ferrule-forming portion, said contact portion comprising a web having contact ears extending from longitudinal edges thereof, portions of said contact ears adjacent to said web being directed inwardly of and over said web, and the end portions of said contact ears extending parallel to each other, arcuate springs integral with and extending from the edges of one of said ears and engaging the other of said ears to maintain the spac ing between the opposed faces of said cars, a longitudinally extending slot in said web having longitudinal edges which are substantially co-planar with the opposed faces of said ears, said ferrule-forming portion comprising an extension of said web and having ferrule-forming ears extending from its longitudinal edges, said ferrule-forming ears being adapted to be bent around and crirnped onto a conductor disposed therebet-Ween, said contact portion being intended to receive a tab through said slot and between said contact ears thereby to establish electrical contact between said tab and the opposed faces of said ears, and tensile stresses are transmitted substantially wholly across the edges of said slot to said tab.

2. An electrical connector comprising a contact portion and a ferrule-forming portion, said contact portion comprising a relatively elongated Web having a slot therein extending in the long irnension thereof, a pair of contact ears, each of said ears being integral with one of the longitudinal edges of said web, said ears extending in the same direction and each extending substantially normally of said Web whereby a tab inserted through said slot is received between said ears, bow springs urging the opposed internal faces of said ears towards each other, each of said bow springs being integral at one end with a side of one of said ears, said ferrule-forming portion comprising an extension of said Web and having ferruleforrning ears extending from its longitudinal edges, said ferrule-forrning ears being adapted to be bent around and crimped onto a conductor received therebetween.

References Cited in the file of this patent UNITED STATES PATENTS 1,531,816 Russell Mar. 31, 1925 1,635,256 Carter July 12, 1927 1,702,451 Phillippi Feb. 19, 1929 2,774,951 Kinka-id et al Dec. 18, 1956 FOREIGN PATENTS 99,5813 Austria Apr. 10, 1925 702,777 Germany Feb. 15, 194 1 54,552 France Oct. 31, 1949 

1. AN ELECTRICAL CONNECTOR COMPRISING A CONTACT PORTION AND A FERRULE-FORMING PORTION, SAID CONTACT PORTION COMPRISING A WEB HAVING CONTACT EARS EXTENDING FROM LONGITUDINAL EDGES THEREOF, PORTIONS OF SAID CONTACT EARS ADJACENT TO SAID WEB BEING DIRECTED INWARDLY OF AND OVER SAID WEB, AND THE END PORTIONS OF SAID CONTACT EARS EXTENDING PARALLEL TO EACH OTHER, ARCUATE SPRINGS INTEGRAL WITH AND EXTENDING FROM THE EDGES OF ONE OF SAID EARS AND ENGAGING THE OTHER OF SAID EARS TO MAINTAIN THE SPACING BETWEEN THE OPPOSED FACES OF SAID EARS, A LONGITUDINALLY EXTENDING SLOT IN SAID WEB HAVING LONGITUDINAL EDGES WHICH ARE SUBSTANTIALLY CO-PLANAR WITH THE OPPOSED FACES OF SAID EARS, SAID FERRULE-FORMING PORTION COMPRISING AN EXTENSION OF SAID WEB AND HAVING FERRULE-FORMING EARS EXTENDING FROM ITS LONGITUDINAL EDGES, SAID FERRULE-FORMING EARS BEING ADAPTED TO BE BENT AROUND AND CRIMPED ONTO A CONDUCTOR DISPOSED THEREBETWEEN, SAID CONTACT PORTION BEING INTENDED TO RECEIVE A TAB THROUGH SAID SLOT AND BETWEEN SAID CONTACT EARS THEREBY TO ESTABLISH ELECTRICAL CONTACT BETWEEN SAID TAB AND THE OPPOSED FACES OF SAID EARS, AND TENSILE STRESSES ARE TRANSMITTED SUBSTANTIALLY WHOLLY ACROSS THE EDGES OF SAID SLOT TO SAID TAB. 